BACKGROUND Transient loss of consciousness (LOC) is one of the most common presentations of aneurysmal subarachnoid hemorrhage (SAH) and may be an indicator of early brain injury. The aim of the current study was to examine the association of LOC to functional outcomes in patients with good-grade SAH.
METHODS We searched the Subarachnoid Hemorrhage International Trialists Repository for patients that presented with LOC at ictus of SAH. A propensity score analysis was performed on good-grade patients (defined as World Federation of Neurosurgical Societies grades 1-3) to balance selected covariates between those with and without LOC. Primary outcome was Glasgow Outcome Score (GOS) at 3 months (with poor outcome defined as GOS of 1-3). Secondary outcomes were delayed cerebral ischemia (DCI), rebleed, length of hospital stay, and time to death.
RESULTS A propensity score-matching algorithm identified 337 patients (168 with LOC at ictus, and 168 without). The proportion of patients with poor functional outcome at 3-months was significantly higher in those who had LOC at ictus compared to the matched cohort without LOC (30% vs. 19%; P = 0.02). There was a non-significant trend toward higher mortality in patients with LOC (19% vs. 13%; P = 0.14). There were no differences in the secondary outcomes.
CONCLUSIONS LOC of at ictus of SAH is associated with higher rate of unfavorable functional outcomes but not mortality, DCI or rebleed in good-grade SAH patients. Future studies should further investigate the putative mechanisms by which LOC mediates early brain injury in SAH.